1. Field of the Invention
The present invention relates generally to a gain control circuit, and is directed more particularly to a gain control circuit which contributes less distortion to a signal to be controlled and in which a DC potential is prevented from fluctuating during control of the signal.
2. Description of the Prior Art
In the art a gain control circuit has been known in which the current flowing through a variable impedance element is controlled to thereby control the gain of the circuit. Such a kind of gain control circuit is disclosed in U.S. Pat. No. 3,678,403 "Balanced Variable Gain Amplifier" by Jack Craft, Assigned to RCA, Issued on July 18, 1972. With such circuits, however, the variable control range cannot be widened very much and its circuit construction becomes complicated.